Free Will and Free Won't

Most of us have a sense that our everyday actions are controlled by an intention that precedes the action: I decide to turn on the light, then flip the switch. But experiments don't consistently support this notion. Some psychologists believe that our sense of intention and purpose is constructed by the brain after the action takes place. Others disagree. The authors discuss ingenious experiments that probe this question, along with bizarre phenomena, such as "alien-hand syndrome," where brain damage leaves patients struggling with actions they cannot control.